Grate the courgette onto a paper towel and squeeze out any excess water.
Put into a mixing bowl.
Grate and drain the carrot, parsnip and potato the same way.
Combine them all in the mixing bowl.
Add the beaten egg and flour, and mix well.
Heat the oil over a medium heat in a large frying pan.
Divide the mixture into 8 pieces of about a tablespoon each.
Put them in the pan in batches that will fit your pan, and flatten down with a fish slice.
Cook for 3-4 minutes on each side until golden brown.
These freeze well after cooking, defrost and reheat in a low oven before serving.